Backlight brightness control method, backlight brightness control device, and display equipment

Abstract

A backlight brightness control method, a backlight brightness control device, and a display equipment are provided. By using a constant current integrated circuit to input constant current to backlight sources in backlight partitions, uniformity of backlight brightness is allowed to be improved. By determining a target peak current inputted to the backlight sources in the backlight partitions according to a grayscale level of partition images, not only can the backlight brightness required by a high grayscale level be ensured, but fine adjustment of the backlight brightness under a low grayscale level can also be ensured.

What is claimed is: 
     
       1. A backlight brightness control method used in a display equipment, wherein the display equipment comprises a display panel and a backlight module providing backlight to the display panel, the backlight module comprises a plurality of backlight partitions, the display panel is configured to display images, the images comprise a plurality of partition images respectively corresponding to the plurality of backlight partitions one-to-one, wherein the backlight brightness control method comprises:
 obtaining an initial duty cycle of pulse width modulation waves of backlight sources in the backlight partitions corresponding to the partition images according to grayscale data of the partition images for any of the partition images; 
 determining peak current adjustment coefficients and duty cycle adjustment coefficients of the pulse width modulation waves according to the initial duty cycle, wherein the peak current adjustment coefficients are positively correlated to the initial duty cycle; 
 determining a target peak current according to the peak current adjustment coefficients and a pre-obtained initial peak current of the backlight sources in the backlight partitions, and determining a target duty cycle according to the duty cycle adjustment coefficients and the initial duty cycle; and 
 inputting the target peak current and the pulse width modulation waves having the target duty cycle to the backlight sources in the backlight partitions; 
 wherein determining the peak current adjustment coefficients and the duty cycle adjustment coefficients of the pulse width modulation waves according to the initial duty cycle comprises: 
 using corresponding peak current adjustment coefficients of initial duty cycle intervals including the initial duty cycle as the peak current adjustment coefficients of the backlight sources in the backlight partitions according to a corresponding relation between the initial duty cycle intervals and the peak current adjustment coefficients; and 
 using reciprocals of the peak current adjustment coefficients as the duty cycle adjustment coefficients of the pulse width modulation waves of the backlight sources in the backlight partitions. 
 
     
     
       2. The backlight brightness control method as claimed in  claim 1 , wherein after inputting the target peak current and the pulse width modulation waves having the target duty cycle to the backlight sources in the backlight partitions further comprises:
 determining target duty cycle intervals according to the initial duty cycle intervals and the duty cycle adjustment coefficients; and 
 realizing brightness adjustment of the backlight sources in the backlight partitions by adjusting a duty cycle of the pulse width modulation waves in the target duty cycle intervals. 
 
     
     
       3. The backlight brightness control method as claimed in  claim 2 , wherein determining the target duty cycle intervals according to the initial duty cycle intervals and the duty cycle adjustment coefficients comprises:
 determining a minimum endpoint value in the initial duty cycle intervals in which the initial duty cycle falls within; 
 multiplying the minimum endpoint value by the duty cycle adjustment coefficients to obtain a minimum target endpoint value; and 
 using intervals composed of the minimum target endpoint value and a maximum target endpoint value as the target duty cycle intervals, wherein the maximum target endpoint value is 100%. 
 
     
     
       4. The backlight brightness control method as claimed in  claim 3 , wherein the initial duty cycle intervals are respectively [0, 25%], (25%, 50%], (50%, 75%], and (75%, 100%], and correspondingly the peak current adjustment coefficients are respectively 0.25, 0.5, 0.75, and 1, and the target duty cycle intervals are respectively [0, 100%], (50%, 100%], (66.7%, 100%], and (75%, 100%]. 
     
     
       5. The backlight brightness control method as claimed in  claim 1 , wherein obtaining the initial duty cycle of the pulse width modulation waves of the backlight sources in the backlight partitions corresponding to the partition images according to the grayscale data of the partition images comprises:
 performing a digital-to-analog conversion on the grayscale data of the partition images to obtain the initial duty cycle of the pulse width modulation waves of the backlight sources in the backlight partitions corresponding to the partition images. 
 
     
     
       6. The backlight brightness control method as claimed in  claim 1 , wherein determining the target peak current according to the peak current adjustment coefficients and the pre-obtained initial peak current of the backlight sources in the backlight partitions, and determining the target duty cycle according to the duty cycle adjustment coefficients and the initial duty cycle comprise:
 multiplying the initial peak current by the peak current adjustment coefficients to obtain the target peak current, and multiplying the initial duty cycle by the duty cycle adjustment coefficients to obtain the target duty cycle. 
 
     
     
       7. A control device used in a display equipment, wherein the display equipment comprises a display panel and a backlight module providing backlight to the display panel, the backlight module comprises a plurality of backlight partitions, the display panel is configured to display images, the images comprise a plurality of partition images respectively corresponding to the plurality of backlight partitions one-to-one, wherein the control device comprises a control board, and the control board performs operations comprising:
 obtaining an initial duty cycle of pulse width modulation waves of backlight sources in the backlight partitions corresponding to the partition images according to grayscale data of the partition images for any of the partition images; 
 determining peak current adjustment coefficients and duty cycle adjustment coefficients of the pulse width modulation waves according to the initial duty cycle, wherein the peak current adjustment coefficients are positively correlated to the initial duty cycle; 
 determining a target peak current according to the peak current adjustment coefficients and a pre-obtained initial peak current of the backlight sources in the backlight partitions and to determining a target duty cycle according to the duty cycle adjustment coefficients and the initial duty cycle; and 
 inputting the target peak current and the pulse width modulation waves having the target duty cycle to the backlight sources in the backlight partitions; 
 wherein determining the peak current adjustment coefficients and the duty cycle adjustment coefficients of the pulse width modulation waves according to the initial duty cycle comprises: 
 using corresponding peak current adjustment coefficients of initial duty cycle intervals including the initial duty cycle as the peak current adjustment coefficients of the backlight sources in the backlight partitions according to a corresponding relation between the initial duty cycle intervals and the peak current adjustment coefficients; and 
 using reciprocals of the peak current adjustment coefficients as the duty cycle adjustment coefficients of the pulse width modulation waves of the backlight sources in the backlight partitions. 
 
     
     
       8. The backlight brightness control device as claimed in  claim 7 , wherein the operations further comprise:
 determining target duty cycle intervals according to the initial duty cycle intervals and the duty cycle adjustment coefficients; and 
 realizing brightness adjustment of the backlight sources in the backlight partitions by adjusting a duty cycle of the pulse width modulation waves in the target duty cycle intervals. 
 
     
     
       9. The backlight brightness control device as claimed in  claim 8 , wherein determining the target duty cycle intervals according to the initial duty cycle intervals and the duty cycle adjustment coefficients comprises:
 determining a minimum endpoint value in the initial duty cycle intervals in which the initial duty cycle falls within; 
 multiplying the minimum endpoint value by the duty cycle adjustment coefficients to obtain a minimum target endpoint value; and 
 using intervals composed of the minimum target endpoint value and a maximum target endpoint value as the target duty cycle intervals, wherein the maximum target endpoint value is 100%. 
 
     
     
       10. The backlight brightness control device as claimed in  claim 9 , wherein the initial duty cycle intervals are respectively [0, 25%], (25%, 50%], (50%, 75%], and (75%, 100%], and correspondingly the peak current adjustment coefficients are respectively 0.25, 0.5, 0.75, and 1, and the target duty cycle intervals are respectively [0, 100%], (50%, 100%], (66.7%, 100%], and (75%, 100%]. 
     
     
       11. The backlight brightness control device as claimed in  claim 7 , wherein obtaining the initial duty cycle of the pulse width modulation waves of the backlight sources in the backlight partitions corresponding to the partition images according to the grayscale data of the partition images comprises:
 performing a digital-to-analog conversion on the grayscale data of the partition images to obtain the initial duty cycle of the pulse width modulation waves of the backlight sources in the backlight partitions corresponding to the partition images. 
 
     
     
       12. The backlight brightness control device as claimed in  claim 7 , wherein determining the target peak current according to the peak current adjustment coefficients and the pre-obtained initial peak current of the backlight sources in the backlight partitions, and determining the target duty cycle according to the duty cycle adjustment coefficients and the initial duty cycle comprise:
 multiplying the initial peak current by the peak current adjustment coefficients to obtain the target peak current and to multiply the initial duty cycle by the duty cycle adjustment coefficients to obtain the target duty cycle. 
 
     
     
       13. A display equipment, comprising a control device, a display panel, and a backlight module providing backlight to the display panel, the backlight module comprises a plurality of backlight partitions, the display panel is configured to display images, the images comprise a plurality of partition images respectively corresponding to the plurality of backlight partitions one-to-one, wherein the control device comprises a control board, and the control board performs operations comprising:
 obtaining an initial duty cycle of pulse width modulation waves of backlight sources in the backlight partitions corresponding to the partition images according to grayscale data of the partition images for any of the partition images; 
 determining peak current adjustment coefficients and duty cycle adjustment coefficients of the pulse width modulation waves according to the initial duty cycle, wherein the peak current adjustment coefficients are positively correlated to the initial duty cycle; 
 determining a target peak current according to the peak current adjustment coefficients and a pre-obtained initial peak current of the backlight sources in the backlight partitions and to determining a target duty cycle according to the duty cycle adjustment coefficients and the initial duty cycle; and 
 inputting the target peak current and the pulse width modulation waves having the target duty cycle to the backlight sources in the backlight partitions; 
 wherein determining the peak current adjustment coefficients and the duty cycle adjustment coefficients of the pulse width modulation waves according to the initial duty cycle comprises: 
 using corresponding peak current adjustment coefficients of initial duty cycle intervals including the initial duty cycle as the peak current adjustment coefficients of the backlight sources in the backlight partitions according to a corresponding relation between the initial duty cycle intervals and the peak current adjustment coefficients; and 
 using reciprocals of the peak current adjustment coefficients as the duty cycle adjustment coefficients of the pulse width modulation waves of the backlight sources in the backlight partitions. 
 
     
     
       14. The display equipment as claimed in  claim 13 , wherein the operations further comprise:
 determining target duty cycle intervals according to the initial duty cycle intervals and the duty cycle adjustment coefficients; and 
 realizing brightness adjustment of the backlight sources in the backlight partitions by adjusting a duty cycle of the pulse width modulation waves in the target duty cycle intervals.